Construction module, panel and system

ABSTRACT

A module for a construction system is disclosed which can be used to form building panels and three-dimensional structures that may include self-supporting cladding. In one form the basic module (10, FIG. 1A, drawing  e!) is formed from two pleated hexagonal plates (11a and 14a) joined together at their peripheries with their concave sides together and with the ridges on one opposite the valleys of the other. Each plate is formed from a blank (11 and 14, respectively) which is a hexagon distorted by extending the radii which will form the valleys of the plate with respect to the radii of a regular hexagon (drawings  a! and  b!).

TECHNICAL FIELD

This invention relates to polygonal construction modules which combinestructural and cladding properties. It is concerned with two-dimensionalconstruction panels--as might be used for weather-proof roots orwalls--formed by joining a plurality of such modules edge-to-edge. Italso relates to fully or partially cladded three-dimensional structuresformed from a plurality of such panels. The modules of particularinterest are those of hexagonal, octagonal, square or rectangular shape,but the panels and structures formed using these modules may alsoincorporate other modular elements. The invention is also concerned withconstruction systems using the modules and panels.

The modules, panels and construction systems of this invention may beemployed in a wide range of applications, such as: for the constructionof temporary or permanent housing, sheds, barns, garages, huts and thelike; for the construction of self-supporting greenhouses, patio covers,awnings, shades, temporary weather shields and the like; for internallinings, partitions, display panels and the like; and for use inrecreation as toys, construction kits, cubby-houses, play-groundstructures and the like.

BACKGROUND OF THE INVENTION

Many construction systems based on frame structures with tetrahedral,hexagonal and/or octagonal modules have been proposed and used. Forexample, Australian Patent No 475,424 discloses a geodesic space-framestructure of icosahedral shape having pentagonal and hexagonal modules.These modules were themselves formed from isosceles triangles so thatthe dome-like structure could be cladded with triangular-shapedsheet-material modules. While such geodesic structures (as pioneered bythe American inventor Richard Buckmainster Fuller) are essentiallydome-like, a great variety of strut-and-node space-frames based ontetrahedral, hexahedral, and octahedral modules are also known andwidely used (see, for example Australian patent No 460,682). These arealso commonly clad with sheet-material panels of similar modularpolygonal shapes, but the cladding panels rarely contribute to theload-bearing capacity of the structure and are not self-supporting.

English architect Arthur Quarmby, and others following his lead (eg,U.S. Pat. No. 4,359,842 to Hooker), proposed a variety ofself-supporting structures formed by the pleating or folding of largesheets of material, typically glass-reinforced plastic. Many exampleswere offered in his book "The Plastics Architect" published by Pall MallPress, London, 1975. Full structures were formed by unfolding largesheets on-site to form vaults, domes or hutments complete with roofs andwalls, the erection process being much like the expansion of bellows.Such structures were tailored individually for their sites and foldedfor transport. However, the large sheets of material could not bedismantled into smaller modules or components for transport so that, forall but the smallest buildings, on-site construction of the sheets wasessential thereby eliminating the advantage of factory production.

U.S. Pat. No. 3,914,486 to Borgford discloses the production ofconstruction panels by pressing a modular hexagonal pattern into a largeplate, but such large plates are expensive to press and difficult tohandle and transport. U.S. Pat. No. 3,931,697 to Pearce, on the otherhand, discloses the use of six different polygonal molecules to formdomes and curved structures. The module of most relevance here is aradially pleated, `minimal surface` hexagon in which ridges and valleysdo not alternate so that bilateral skewing or `saddling` results. Theseasymmetric modules are difficult to assemble into structures (requiringfive other module types) and cannot be joined together in planar panels,as required for the walls of common rectangular buildings.

U.S. Pat. No. 4,723,382 (and the continuations hereof) to Lalvinidiscloses a large variety of nodal, periodic and non-periodic,space-frame and panel structures based upon `golden polyhedra` anddistortions thereof. The most relevant of these are called `saddlezonogons` and `saddle zonohedra` derived from the radial folding orskewing of plates. Such modules are similar to some of those disclosedby Pearce and suffer from the same disadvantages indicated above.

OBJECTIVES OF THE INVENTIONS

The objective of the invention is to provide a simple modularconstruction panel which can be assembled into sheets or structures withintegral structural strength and yet be suitable for mass production andtransport. More generally, it is the object of the invention to providean improved modular construction panel, and panel-sheets, structures andconstruction systems based thereon.

OUTLINE OF THE INVENTION

The present invention is based upon the realisation that combinedcladding and structural modules can be constructed by bracing radiallypleated and dished polygonal plates on their concave sides, either witha bracing `spider` or with a second polygonal plate of substantially thesame shape and pleated form as the first plate, the two plates beingwith their concave faces together. In this context, `pleating` meansthat ridges and valleys alternate around the polygonal plate and that,therefore, the polygon must have an even number of sides. Particularlysuitable polygons for such modules in profile are those of a rectangle(including a square), and a regular hexagon or octagon, the hexagonbeing preferred (though the invention is not limited to either shape). Amodule formed from two pleated plates in the manner indicated will belight-weight, stiff and hollow, but it can be further strengthened bysecuring the sides together by plastics foam, by the use of internalpillars or webs, or by in-pleating to dimple the plates (even to thedegree that their centres touch).

Such modules (when viewed side-on) will have undulating edges as theiradjacent edges will be angled to one another by less than the normalangle for the respective regular polygon. For example, the angle betweentwo adjacent sides of a hexagonal module (when viewed from the edge ofthe module) will be less than 120° though the angle of the same to sidesviewed in projection from the face of the module will be 120°. The firstangle is called the `edge angle` of a module. Provided modules have thesame edge angles they can be joined together by their edges to formpanels (which extend in essentially two dimensions). The joining of onemodule to another may be effected in any one of many ways known in theart, but this will usually be achieved by using flanges formed aroundthe periphery of each module for the purpose. When the flanges extendin-line with the plane of the module, one row of modules in a panel mayoverlap the next like roof-tiling to facilitate weather-proofing. Whenthe flanges are turned at right angles to the plane of the module, theycan be readily welded, glued, clipped, riveted, stitched or boltedtogether. Joining strips may also be employed. Of course, theorientation of the flanges between adjacent plates and the method ofjoining the flanges and plates will depend to some degree upon thematerial of the plates. Since modules formed from two plates are hollow,they can be filled with plastics foam or the like to improve rigidityand insulation properties.

Any suitable stiff sheet material may be used for the plates, examplesbeing plastic, metal, cellulose card, reinforced cement/concrete orfibre-board. The plates may be profile-cut in any suitable manner, as bylaser-cutting, blanking or guillotining and may be pleated by folding,creasing or pressing. It is also envisaged that plastics, cellulose orfibre-board plates could be formed in a hot pressing operation, whilemetal plates could be stamped-out in one operation. As the modules neednot be large (ie, meters across), they can be easily mass-produced andtransported in finished form or as stacks of pleated plates (or spiders)ready for assembly.

It should be noted that, in order to form a module which is a regularpolygon (in projection) the blank for a plate cannot be a regularpolygon. Those pleat-lines which form ridges will be shorter than thosewhich form valleys, the difference in their lengths determining thedepth of pleating and the thickness of the module. The ratio of thelengths of a valley to a ridge of a blank (or plate) is an importantparameter and is called the `pleat ratio`. This ratio determines thedepth of pleating (or the thickness of the module), and the edge angleand, thus, the degree of dimpling of the surface of a panel. This, inturn therefore, determines the minimum angle at which a panel can bedisposed to the horizontal before puddling occurs in the dimples duringrain. It also determines the non-zero (or non-180°) `transition angle`at which one panel will join to another `naturally` without the need forcorner modules (here-after called sub-modules). For example, a pleatingratio of 1.05 allows a transition angle of 120° (included angle) betweentwo panels formed from hexagonal modules, while a pleating ratio of 1.18allows a transition angle of 90° for similar panels.

Thus, the principal terms used in this specification are as follows:

`Module` indicates a braced and pleated polygonal plate, the bracing bythe use of a spider or (more preferably) by the use of a second pleatedplate.

`Plate` indicates a sheet of material of polygonal shape (usuallyrectangular, hexagonal or octagonal) which is radially pleated to form acomponent of a module, an un-pleated plate being referred to as a`blank`. A bracing plate need not be continuous as portions of its blankcan be cut away to reduce its weight to create (for example) aspider-like lattice of triangles.

`Spider` indicates a star-shaped structure used for bracing a pleatedplate to complete a module.

`Panel` indicates a plurality of modules assembled edge to edge to forma generally planar (two-dimensional) array. A panel may, for example,form the wall or roof of a hut (or part thereof).

`Structure` indicates at least two panels assembled at an angle to oneanother and is, therefore, three dimensional in character. A structuremay be, for example, a gabled roof, an arch or a hut.

DESCRIPTION OF EXAMPLES

Having broadly portrayed the nature of the present invention, particularembodiments will now be described by way of example and illustrationonly. In the following description, reference will be made to theaccompanying drawings in which:

FIG. 1A illustrates the manner in which a hexagonal module is formedfrom a pair of plates, while FIG. 1B shows the formation of a hexagonalmodule from a plate and a spider.

FIG. 2A illustrates the manner in which an octagonal module is formedfrom a pair of plates, while FIG. 2B shows the formation of an octagonalmodule from a plate and a spider.

FIG. 3A is an elevation of a vertical panel formed from hexagonalmodules, FIG. 3B being a sectional elevation taken on plane 3--3 of FIG.3A, while FIG. 3C is a perspective view of the panel of FIG. 3A.

FIG. 4A is an elevation of a vertical panel formed from octagonalmodules, FIG. 4B being a sectional elevation taken on plane 4--4 of FIG.4A, while FIG. 4C is a perspective view of the panel of FIG. 4A.

FIG. 5A is a plan view of a horizontal panel formed from hexagonalmodules which overlap one another in the manner of roof tiling, whileFIG. 5B is a diagrammatic sectional elevation of the panel of FIG. 5Ataken on plane 5--5.

FIG. 6A is a diagrammatic sectional elevation of a panel showing one wayof joining the modules, while FIG. 6B is a similar view showing anotherway of joining the modules.

FIGS. 7A-7C are cross-sections of modules which have been internallystrengthened in various ways, while FIG. 7D is a plan view of a modulestrengthened by secondary pleating or dimpling, FIG. 7E being a sectionof the module of FIG. 7D taken plane E--E of FIG. 7D.

FIGS. 8A-8C shown modules which are adapted to generate curved panels,FIG. 8A being a plan view of a plate blank modified for the purpose,FIG. 8B being a diagrammatic section of a module formed from two platesformed from blanks of the type shown in FIG. 8A.

FIGS. 9A-9D show the manner in which two panels may be joined alongtheir saw-tooth edges at their characteristic transition angle, eachFigure being a perspective view of a panel or panels.

FIG. 10A is a diagrammatic perspective of a hut or shed having its wallsand roof formed from hexagonal modules, while FIG. 10B is an enlargedand simplified semi-exploded view of the gable peak of the hut or shedof FIG. 10A.

FIG. 11 illustrates the manner in which a square module is formed from apair of different but substantially square pates.

One way in which a hexagonal module 10 may be formed in accordance withthis invention is illustrated by FIG. 1A in drawings a! to e!. A firstplate 11 or blank is cut to a particular hexagonal shape from stiffsheet material (drawing a!), the shape generally being a distortion of aregular hexagon (indicated in broken lines) in that each alternate`radius` (semi-axis or half-diagonal) 12 is lengthened, leaving theother radii (13) unchanged. A substantially identical second plate 14 isformed in the same manner (drawing b!) but is rotated 60° with respectto plate 11 so that its shorter radii 15 are aligned with the longerradii 12 of plate 11 and its longer radii 16 are aligned with theshorter radii 13 of plate 11. First plate 11 is then pleated (eg, byfolding or pressing) so that its lengthened radii (12) form valleys 12aand its normal radii form ridges 13a, forcing the plate into adish-shape with its convex side uppermost, as indicated by arrow 17 indrawing c!. The pleated first plate is indicated at 11a in drawings c!and e!. Plate 14 is similarly pleated to form valleys 16a and ridges15a, forcing it to adopt a concave shape with its convex sidelower-most, as indicted in drawing d! by arrow 18. The pleated secondplate is indicated at 14a in drawings d! and e!. Note that thedesignation of which radii is a valley and which is a ridge isdetermined by viewing each plate from its convex (lower) side, but thathowever viewed, ridges and valleys alternate around the hexagonal shape.Finally, pleated plates 11a and 14a are juxtaposed with their concavefaces together and the ridges 13a of the first opposite the valleys 16aof the second. When these plates are brought together so that theirperipheries are coincident and secured together, they form the module 10which has undulating edges as shown in drawing e!. However, inprojection, module 10 has the shape of (but is slightly smaller in sizethan) the regular hexagon indicated in broken lines in drawings a! andb!.

Another way of forming a hexagonal module 10a is shown in drawings a! toe! of FIG. 1B, upper pleated plate 11a being identical to the firstplate of FIG. 1A (and being referenced accordingly). Instead of using asecond plate to brace the first, this function is performed by astar-shaped spider shown as a flat blank 19 in drawing b! of FIG. 1B.Spider 19 may be bent to form a dished spider 19a (drawings d! and e!and assembled with plate 10a so that the ends of its arms connect to thecorners of pleated plate 11a. It will be appreciated, however, that thespider can be formed so that it remains flat rather than dished and sothat it has only three arms rather than six. In the latter case, it isdesirable to ensure that the arms of the spiders of two adjacent modulesdo not meet at the same plate corners; that is, to ensure that thespider of one module assists in the bracing of an unbraced corner of aneighbouring module.

FIG. 2A illustrates the way in which an octagonal module 20 (drawing e!)may be formed from a pair of flat blanks 21 and 22 of generallyoctagonal shape in which every alternate radius has been lengthened (seedrawings a! and b!). As before, each lengthened radius forms a valleyand each normal radius forming a ridge in the corresponding pleated anddished plates 21a and 22a (see drawings c! and d! respectively). Onceagain, the pleated plates are juxtaposed so that the ridges of one areopposite the valleys of the other (see drawing e!) and are broughttogether so that their peripheral edges coincide and are joined togethercreating module 20. Module 20, when viewed side-on, has undulatingedges. In projection, it has the shape of (but is slightly smaller insize than) the regular octagon indicated in broken lines in drawings a!and b!.

Like the hexagon example, an octahedral module 20 can be formed using aspider, as shown in the drawings a! to e! of FIG. 2B. The first or upperblank 21 and pleated plate 21a are identical with those of FIG. 2A.However, in this case, instead of the six-legged spider of FIG. 1B, aneight-legged spider 22 is shown as a flat `blank` in drawing b!. Thisblank is bent to form the dished spider 22a which is assembled withplate 21 a to form the bracing of module 20a. As indicated with respectto the hexagonal case, there is no need to dish the spider and half ofits legs may be omitted without significant loss of bracing effect.

Turning now to FIGS. 3A to 3C which illustrate a substantiallyrectangular panel 30 formed from hexagonal modules 10 (or 10a) describedabove. It will be seen that one pair of opposing panel edges (32) are ofsaw-tooth shape and that the other pair of opposing edges (34) are ofcastellated shape. Because of the undulating character of the edges ofeach module 10, a grid of depressions or dimples 36 are formed at thejunctions between three adjacent modules and a corresponding grid ofbumps 38 are formed by the apices of the modules (FIG. 3C).

FIGS. 4A-C show a substantially rectangular panel 40 of octagonalmodules 20 and tetrahedronal sub-modules 42, the latter modules beingreferred to as sub-modules as they are of lesser significance from thestandpoint of this invention. It will again be seen that the centres ofthe octahedral modules 20 form a grid of bumps 44, while the junctionsbetween 20 and 42 form a corresponding grid of dimples or depressions46.

FIGS. 5, 6 and 7 show various methods of joining hexagonal modules. InFIG. 5A and 5B each module 50 is formed with a continuous peripheralflange 52 so that the modules can be arranged in horizontal rows withone edge horizontal, so that the lower edge or flange 52 of each module50 overlaps the upper edge or flange of the next lower module, as in thecase of roof-tiling. The modules may be secured together by rivets,screws, clips or bolts generally indicated at 54. Alternative methods ofjoining adjacent modules are indicated by FIGS. 6A and 6B. In theseexamples, each module 60 is formed with edge flanges 62 which are bentat right angles to the plane of the module. In the case of FIG. 6A,flanges 62 are provided with a return lip so that adjacent modules canbe joined together by U-shape clips or strips 64 which can bespot-welded, glued, bolted or simply slid in place. In the case of FIG.6B, the flanges 62 are secured together by fasteners 66.

While the structural rigidity of a module or a panel depends upon thestrength and the stiffness of the sheet material from which the platesare formed, as well as upon the manner in which they are joinedtogether, the stiffness of a module can be enhanced in a number of ways.Some of these are illustrated in FIGS. 7A to 7E. In FIG. 7A, a module70a (shown in section) is strengthened by the use of a central post 71which extends between the apices of the plates 72 and 73 and is rivetedat each end to the respective plate. In FIG. 7B, module 70b (also shownin section) is filled with a solid light-weight plastics foam 74 (suchas polyurethane), to effect the reinforcement. In FIG. 7C, module 70c isfitted with an internal stiffening web 75, but it is also envisaged thata cruciform (or star-shape) web assembly may be used so that the module70c is stiffened along more than one axis. Finally, according to thegeneral principle shown in FIGS. 7D and 7E, a module 70d may bestiffened by secondary in-pleating each plate to invert its apex andform a dimple 76. While it is not essential for the dimples to be starshaped, have facets or for their centres to touch, these features areshown in the drawings and provide excellent stiffening of the module70d. The radiating points of each dimple may be arranged on theridge-pleats of the plate. The centres of dimples 76 may, of course, besecured together by a suitable fastener, further strengthening themodule.

It is possible to form spherically or cylindrically curved panels bysuitable modification of their component modules. In general, this isachieved by forming each module from a pair of blanks which differslightly. For example, one blank may have a different pleating centreand/or a slightly different shape with respect to the other. The firstis illustrated in the example of FIGS. 8A and 8B, the second in FIG. 8C.

The module 80 of FIG. 8B is formed from plates 81 and 82, the blank 83for plate 82 being shown in FIG. 8A. Plate 81 is formed normally; thatis, its pleating centre and the polygon centre of its blank (not shown)coincide at 84. However, the pleating centre 85 of blank 83 is offsetwith respect to its polygonal centre (84'). When a panel is assembledfrom modules 80 which are aligned so that their offset pleating centres(85) are similarly disposed relative to the panel, acylindrically-curved panel will be produced; offsetting of the pleatingcentres of a module being the basis of cylindrical curvature in a panel.

To obtain spherical curvature in a panel, the modules may also beconstructed as illustrated by module 86 in FIG. 8C. That is, one plate87 of each module is also cut slightly smaller than the other plate 88so that, when the module is assembled, it is distorted when the edges ofthe two plates are brought into alignment and fastened.

Planar panels may be joined at angles to form three-dimensionalstructures in a variety of ways, the most versatile being to usesub-modules which have the same edge angles as the panel modules andwhich effect the `turn`. In the case of hexagonal modules, the use ofsuch sub-modules is illustrated in FIGS. 10A and 10B, which show that itis possible to construct and entire hut or shed (with gabled roof) frompanels with hexagonal modules joined with tetrahedronal sub-modules.

To form three dimensional structures by joining planar panels ofhexagonal modules along their edges, use can be made of the natural`transition angle`, T of the panels to be joined (provided they havebeen formed from modules of the same size and pleat ratio). This isillustrated by FIGS. 9A-9D. In FIG. 9A, the two panels 90 and 91 to bejoined at an angle are arranged with their saw-tooth edges toward oneanother (as if they had just been separated). Panel 91 is then turnedup-side-down (as indicated by arrow 93) and the two panels broughttogether so that the undulating edges of the modules forming thesaw-tooth edge are aligned and in contact. When this occurs, the panelswill be at an angle as shown in FIG. 9B, the angle being the transitionangle T corresponding to the component pleating ratio of the componentmodules. If, as shown in FIG. 9C, panel 90 is turned instead of panel 91and the two are brought together in the same manner, they will still bearranged at angle T, but the joint will be inverted, as shown in FIG.9D.

Mathematical analysis shows that, for hexagonal modules, the twopractically important transition angles of 90° and 120° correspond topleat ratios of 1.18 and 1.05, but any desired transition angle can beset by suitably adjusting the pleat ratio of the component modules of apanel. FIGS. 10A and 10B show a shed such as a glass-house 100 formedentirely from hexagonal modules 102 with a pleating ratio of 1.05, butwithout any `natural` transitions between panels. The saw-tooth tosaw-tooth join between the side wall panel 104 and front wall panel 106,as well as the transition between the roof panel 108 and the front wallpanel 106, are effected by the use of tetrahedrons 110 designed to matchthe edge angles of the modules and to effect the necessary turns. Toalign the front wall modules with the roof angle (the included ridgeangle being 120°), a row of tetrahedron modules 112 must also be used.These extend diagonally downwards from the roof-wall junction as shown.

The junction between the side wall and the roof panels involves acastellated edge to a castellated edge and this junction may be effectedby both tetrahedrons and right pyramids or equilateral triangles. Giventhe geometry of the shed, it will be seen that the wall-to-roof angle isthe same as the gable angle (ie, 120°). Therefore, to illustrate thejoint more clearly (and to show how the pinnacle join is accomplished,FIG. 10B shows the arrangement of modules in an enlarged and simplifiedmanner. In this Figure, the hexagonal modules are shown at 102, thetetrahedral modules are shown at 110 and the triangular orright-pyramidal modules are shown at 124. In the structure shown, basedon hexagonal modules with a pleat ratio of 1.05, a total of only fivedifferent blanks (for the hexagonal modules, two types of tetrahedronalsub-modules, and triangles) are required to effect the entireconstruction.

Finally, FIG. 11 illustrates the form of a square module 130 FIG. 11 e!)and the way in which it is formed from two slightly different plates 132and 134. Plate 132 (FIG. 11 a!) is pleated so that its diagonals 136form valleys and its right bisectors 138 form ridges (FIG. 11 c!). Thus,consistent with the hexagonal plates described in the above examples,the four sides of plate 132 are distorted by lengthening the diagonals.On the other hand, plate 134 (FIG. 11 b!) is pleated so that itsdiagonals 140 form ridges and its right bisectors 142 form valleys (FIG.11 d!. Again, consistent with the hexagonal plates described in theabove examples, the four sides of plate 134 are distorted by lengtheningthe right bisectors. These pleated plates are then assembled withvalleys opposing ridges as illustrated in FIG. 11 e!. Panels andstructures may then be formed from modules 130. It will be appreciatedthat the same principles can be applied to the formation of non-squarerectangular modules.

It will be appreciated that the examples of the invention describedabove meet the objects and advantages set out at the beginning of thisspecification. However, those skilled in the art will also understandthat many variations and modifications can be made to the invention asdisclosed without departing from the scope of the following claims.

I claim:
 1. A polygonal constructional module having a shape in outlineselected from the group comprising rectangles, squares, hexagons andoctagons, said module comprising:a first plate of polygonal shape havinga center, a peripheral edge, a plurality of corners spaced around saidperipheral edge and having a first side surface and a second sidesurface opposite said first side surface, pleats extending from saidcorners toward the center of said first plate to form alternating ridgesand valleys around said first plate thereby causing said first plate tobe dished so that said first side surface is concave and said secondside surface is convex, a second plate of polygonal shape having acenter, a peripheral edge, a plurality of corners spaced around saidperipheral edge of said second plate and having a first side surface anda second side surface opposite said first side surface of said secondplate, and pleats extending from said corners of the second plate towardthe centre of the second plate to form alternating ridges and valleysaround said second plate thereby causing said second plate to be dishedso that said first side surface of the second plate is concave and saidsecond side surface of the second plate is convex, and wherein saidfirst and second plates are aligned, superimposed and joined at theirrespective peripheral edges so that (i) their concave side surfaces faceone another and enclose a space there-between, and (ii) at least one ofthe ridges on the concave side surface of said first plate is alignedwith at least one of the valleys on the concave side surface of saidsecond plate.
 2. The module of claim 1 wherein:each ridge of the concaveside surface of said first plate is aligned opposite a respective valleyof the concave side surface of said second plate, the length of eachvalley of each plate is greater than the length of each ridge of therespective plate, the ratio of the length of each valley to the lengthof each ridge in one of said plates is the same as the ratio of thelength of each valley to the length of each ridge in the other of saidplates, and wherein the module thus formed has an undulating peripheraledge.
 3. The module of claim 2 wherein the module has a hexagonal shapeand said ratio is 1.05.
 4. The module of claim 2 wherein the module hasa hexagonal shape and said ratio is 1.18.
 5. The module of claim 2wherein the ridges and valleys of each plate converge at the center ofthe respective plate.
 6. The module as claimed in claim 2 wherein theridges and valleys of each plate converge at a point displaced from thecenter of the respective plate, thereby imparting a cylindricalcurvature to the module.
 7. The module as claimed in claim 2 whereinsaid second plate is smaller than said first plate, thereby imparting aspherical curvature to the module.
 8. The module as claimed in claim 2wherein a dimple is formed in the center of the convex side surface ofat least one of said plates thereby increasing the rigidity of themodule.
 9. A planar panel comprising a plurality of interconnectedmodules formed in accordance with clamp 2 wherein:the panel has a firstside face and a second side face, each of said panel side faces has aregular pattern of depressions formed therein by the junction of thevalleys in the convex second side surfaces of the plates of adjacentmodules, and each of said panel side faces has a regular pattern ofmounds formed thereon by the junction of the ridges of adjacent modules.10. The panel of claim 9 wherein:the panel is of a substantiallyrectangular shape and has two pairs of opposing edges, and each edge ofone pair of said opposing edges of the panel is of saw-tooth shape, eachedge of the other pair of said opposing edges of the panel is ofcastellated shape.
 11. The panel claimed in claim 10 wherein:each ofsaid modules is of hexagonal shape, and a plurality of tetrahedronalsub-modules are joined to the hexagonal modules of the panel along atleast one of said panel edges which is of saw-tooth shape.
 12. The panelclaimed in claim 9 wherein:the panel is formed from a plurality ofadjacent rows of said modules, each row of modules having a firstlongitudinal edge and a second longitudinal edge, and wherein said firstlongitudinal edge of one of said rows of modules overlaps said secondedge of an adjacent row of modules.
 13. The panel claimed in claim 9wherein:tabs are formed on the peripheral edges of at least one plate ofeach module so as to extend at an angle with respect thereto, andfastener means are employed to secure the tabs of adjacent modulestogether to form the panel.
 14. A panel wherein:said panel is formedfrom a plurality of modules of octagonal shape formed in accordance withclaim 2 and a plurality of sub-modules of tetrahedronal form, saidoctagonal modules and said sub-modules are joined together to cover aplanar area so that said panel has a first side surface and a secondopposing side surface and a plurality of side edges, and each of saidside surfaces of the panel has a regular pattern of depressions thereinformed at junctions of said octagonal modules and said sub-modules. 15.A three-dimensional structure created by joining a plurality of panelsformed as claimed in claim 11, wherein:a first one of said panels isjoined along one of its edges of saw-tooth shape to the edge of a secondpanel which is also of saw-tooth shape in such a manner as to leave nogaps, and said first and said second panels are arranged at an angle toone another.
 16. A three-dimensional structure comprising a first panelformed as claimed in claim 14 joined by one side edge thereof to oneside edge of a second panel also formed as claimed in claim 14, so thatsaid first panel is arranged at an angle to said second panel, andwherein:sub-modules having the shape of tetrahedrons are employed tojoin said one side edge of the first panel to said one side edge of saidsecond panel.